Commands by GriseldaJoyce (0)

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Carriage return for reprinting on the same line
The above code is just an example of printing on the same line, hit Ctrl + C to stop When using echo -ne "something\r", echo will: - print "something" - dont print a new line (-n) - interpret \r as carriage return, going back to the start of the line (-e) Remember to print some white spaces after the output if your command will print lines of different sizes, mainly if one line will be smaller than the previous Edit from reading comments: You can achieve the same effect using printf (more standardized than echo): while true; do printf "%-80s\r" "$(date)"; sleep 1; done

floating point operations in shell scripts
allows you to use floating point operations in shell scripts

Show current working directory of a process

Arch Linux: Always install software without asking
Adding this alias to ~/.bashrc or, better yet, the system-wide /etc/bash.bashrc (as in my setup) will make it possible to not only run pacman as any user without needing to prepend sudo but will also ensure that it always assumes that the user knows what he or she is doing. Not the best thing for large multi-user enterprise setups at all to say the least, but for home (desktop) use, this is a fantastic time-saver.

Play all files in the directory using MPlayer
Skip forward and back using the < and > keys. Display the file title with I.

Find usb device in realtime
Using this command you can track a moment when usb device was attached.

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

Destroy all disks on system simultaneously
This command will use the fdisk utility to find all block devices on your system, and overwrite them with data from the /dev/urandom non-blocking random number generator. CAUTION: This will irrevocably erase EVERY SINGLE physical block storage device visible to the fdisk utility, including plugged USB devices, RAID sets, LVM, etc.

Geolocate a given IP address
GeoIP Needs to be installed. Can be done from some distro's or via MaxMind.com for free. There even is a free city database availabble. If the GeoLiteCity is downloaded and installed it will also find more information $ geoiplookup -f /var/lib/GeoIP/GeoLiteCity.dat commandlinefu.com GeoIP City Edition, Rev 1: US, NJ, Absecon, 08201, 39.420898, -74.497704, 504, 609

display a smiling smiley if the command succeeded and a sad smiley if the command failed
you could save the code between if and fi to a shell script named smiley.sh with the first argument as and then do a smiley.sh to see if the command succeeded. a bit needless but who cares ;)

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